Justyna Czekirda

• Etzelmüller, Bernd; Patton, Henry; Schomacker, Anders; Czekirda, Justyna; Girod, Luc Maurice Ramuntcho; Hubbard, Alun Lloyd; Lilleøren, Karianne Staalesen & Westermann, Sebastian (2020). Icelandic permafrost dynamics since the Last Glacial Maximum – model results and geomorphological implications. Quaternary Science Reviews.  ISSN 0277-3791.  233:106236, s 1- 15 . doi: 10.1016/j.quascirev.2020.106236 Fulltekst i vitenarkiv. Vis sammendrag

  Iceland’s periglacial realm is one of the most dynamic on the planet, with active geomorphologicalprocesses and high weathering rates of young bedrock resulting in high sediment yields and ongoingmass movement. Permafrost is discontinuous in Iceland’s highlands and mountains over c. 800 m a.s.l,and sporadic in palsa mires in the central highlands. During the late Pleistocene and Holocene, Iceland’speriglacial environment varied considerably in time and space, dominated by glacialfluctuations andperiglacial processes. To evaluate the dynamics of permafrost in Iceland since the last deglaciation, weuse the output of a coupled climate/ice sheet model to force a transient permafrost model (CryoGRID 2)from the Last Glacial Maximum (LGM) through to the present. Wefind that permafrost was widespreadacross the deglaciated areas of western, northern and eastern Iceland after the LGM, and that up to 20% ofIceland’s terrestrial area was underlain by permafrost throughout the late Pleistocene. This influencedgeomorphological processes and landform generation: the early collapse of the marine-based ice sheettogether with the aggradation of permafrost in these zones initiated the formation of abundant and nowrelict rock glaciers across coastal margins. Permafrost degraded rapidly after the Younger Dryas, with amarked impact on slope stability. Permafrost that formed during the Little Ice Age is again thawingrapidly, and an escalation in slope failure and mass-movement might be currently underway. Our studydemonstrates that large regions of Iceland have been underlain by permafrost for millennia, facilitatinglandform development and influencing the stability of steep slopes

• Czekirda, Justyna; Westermann, Sebastian; Etzelmüller, Bernd & Jóhannesson, Tómas (2019). Transient Modelling of Permafrost Distribution in Iceland. Frontiers in Earth Science.  ISSN 2296-6463.  7(130) . doi: 10.3389/feart.2019.00130 Fulltekst i vitenarkiv.

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• Etzelmüller, Bernd; Patton, Henry; Schomacker, Anders; Hubbard, Alun Lloyd; Czekirda, Justyna & Westermann, Sebastian (2019). Permafrost dynamics in Iceland between 18 ka BP and today – model results and geomorphological implications. Vis sammendrag

  Periglacial processes and the dynamics of permafrost is a decisive factor for slope stability locally, and for understanding landscape development over longer time scales. Iceland has a highly dynamic landscape because of young bedrock and associated high geomorphological process rates, leading to large material production and frequent gravitational processes in the present periglacial realm. At present, permafrost in Iceland is widespread in mountain settings over c. 800 m a.s.l. and sporadically in palsa mires in the central Highlands. However, during the late Pleistocene and Holocene, the periglacial environment in Iceland must have varied strongly in time and space, with subsequent imprint in the landscape. To evaluate the dynamics of permafrost in Iceland since the onset of the last deglaciation, we used the forcing and output of a 3D, time-integrated ice sheet model to run a transient permafrost model (CryoGRID 2) between the onset of the last deglaciation (c. 18 ka BP) until today. The permafrost model was forced by either modeled sub-glacial temperatures if ice-covered, or air temperatures if the area was deglaciated. The results give insights into the possible age of permafrost in Iceland, distinguish areas with wide-spread paleo-permafrost and let us determine the persistence of permafrost in the different areas. The presentation discusses these results in the light of periglacial processes, landforms and landscape development

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